ML051090356
| ML051090356 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/06/2005 |
| From: | Mahesh Chawla NRC/NRR/DLPM/LPD3 |
| To: | Solymossy J Nuclear Management Co |
| Chawla M, NRR/.DLPM, 415-8371 | |
| References | |
| TAC MC6756 | |
| Download: ML051090356 (5) | |
Text
April 26, 2005 Mr. Joseph M. Solymossy Site Vice President Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC 1717 Wakonade Drive East Welch, MN 55089
SUBJECT:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 2 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (MC6756)
Dear Mr. Solymossy:
Inservice inspections of steam generator (SG) tubes play a vital role in assuring that adequate structural integrity of the tubes is maintained. As required by the plant technical specifications, reporting requirements range from submitting a special report, within 15 days following completion of each inservice inspection of SG tubes, that identifies the number of tubes plugged and/or repaired; to submitting a special report, within 12 months following completion of the inspection, that provides complete results of the SG tube inservice inspection. The special report containing the complete results shall include the following:
- 1. Number and extent of tubes inspected.
- 2. Location and percent of wall-thickness penetration for each indication of an imperfection.
- 3. Identification of tubes plugged and/or repaired.
A phone conference has been arranged with members of your staff to discuss the ongoing results of the SG tube inspections to be conducted during the upcoming Prairie Island Nuclear Generating Plant, Unit 2 refueling outage. This phone call will occur after the majority of the tubes have been inspected, but before the SG inspection activities have been completed.
Enclosed is a list of discussion points to facilitate this phone conference.
The U.S. Nuclear Regulatory Commission (NRC) staff plans to document a brief summary of the conference call as well as any material that you may have provided to the NRC staff in support of the call.
Sincerely,
/RA/
Mahesh L. Chawla, Project Manager, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-306
Enclosure:
List of Discussion Points cc w/encl: See next page
ML051090356 OFFICE PDIII-1/PM PDIII-1/LA EMCB:SC PDIII-1/SC NAME MChawla THarris LLund LRaghavan DATE 4/25/05 4/22/05 4/25/05 4/26/05
Prairie Island Nuclear Generating Plant, Units 1 and 2 cc:
Jonathan Rogoff, Esquire Vice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Manager, Regulatory Affairs Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC 1717 Wakonade Drive East Welch, MN 55089 Manager - Environmental Protection Division Minnesota Attorney Generals Office 445 Minnesota St., Suite 900 St. Paul, MN 55101-2127 U.S. Nuclear Regulatory Commission Resident Inspector's Office 1719 Wakonade Drive East Welch, MN 55089-9642 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60532-4351 Administrator Goodhue County Courthouse Box 408 Red Wing, MN 55066-0408 Commissioner Minnesota Department of Commerce 85 7th Place East, Suite 500 St. Paul, MN 55101-2198 Tribal Council Prairie Island Indian Community ATTN: Environmental Department 5636 Sturgeon Lake Road Welch, MN 55089 Nuclear Asset Manager Xcel Energy, Inc.
414 Nicollet Mall, R.S. 8 Minneapolis, MN 55401 John Paul Cowan Executive Vice President & Chief Nuclear Officer Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Craig G. Anderson Senior Vice President, Group Operations Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 November 2004
ENCLOSURE STEAM GENERATOR TUBE INSPECTION DISCUSSION POINTS PREPARED BY THE OFFICE OF NUCLEAR REACTOR REGULATION NUCLEAR MANAGEMENT COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 2 DOCKET NO. 50-306 The following discussion points have been prepared to facilitate the phone conference arranged with Nuclear Management Company to discuss the results of the steam generator (SG) tube inspections to be conducted during the upcoming Prairie Island Nuclear Generating Plant, Unit 2 refueling outage. This phone call is scheduled to occur towards the end of the planned SG tube inspection interval, but before the unit completes the inspections and repairs.
The U.S. Nuclear Regulatory Commission (NRC) staff plans to document a brief summary of the conference call as well as any material that is provided in support of the call.
1.
Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.
2.
Discuss whether any secondary side pressure tests were performed during the outage and the associated results.
3.
Discuss any exceptions taken to the industry guidelines.
4.
For each SG, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion-transition, U-bends with a rotating probe), the scope of the inspection (e.g., 100 percent of dents/dings greater than 5 volts and a 20 percent sample between 2 and 5 volts), and the expansion criteria. Also, discuss the extent of the rotating probe inspections performed in the portion of tube below the expansion transition region (reference NRC Generic Letter 2004-01, Requirements for Steam Generator Tube Inspections).
5.
For each area examined (e.g., tube supports, dent/dings, sleeves, etc), provide a summary of the number of indications identified to-date of each degradation mode (e.g.,
number of circumferential primary water stress corrosion cracking indications at the expansion transition). For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).
6.
Describe repair/plugging plans.
7.
Describe in-situ pressure test and tube pull plans and results (as applicable and if available).
8.
Provide the schedule for steam generator-related activities during the remainder of the current outage.
9.
Discuss the following regarding loose parts:
- what inspections are performed to detect loose parts
- a description of any loose parts detected and their location within the SG
- if the loose parts were removed from the SG
- indications of tube damage associated with the loose parts
- the source or nature of the loose parts if known